a few of the pieces that I had for the top have some pretty significant knot holes:

Now, for the most part, these will end up on the bottom out in the middle where they shouldnt be an issue, but, for the sake of it, I would like to fill them up to seal them and avoid having too much of a weak spot in the bench.

I’ve never really had to fill big imperfections before and was wondering if any of you had suggesions on what to do here?

Do i carve a piece that will fill most of the hollow and then fill with some sort of epoxy? if so, what epoxy do you suggest? (I’ve never really had to use any before)

Much appreciated!

-Will

-- Will, Ontario Canada. "I can do fast, cheap and good, but you can only pick two... "

16 replies so far

Do you have other pieces that you could use for the top, or do to have to use these boards? I’ve never filled knot holes quite that large, but I have used epoxy on smaller knots in the past with relatively good success.

Using epoxy in that much volume will generate a lot of heat when it’s curing. I don’t think that would be a big problem, but there is the chance it may crack the boards.

Personally, it looks like you have enough clear wood for the top based on your blog. There will be enough wood glued to the sides of these pieces that these voids will not substantially weaken the top.

If you’re really set on filling them, probably the best option is to square off the area around the knot holes and fill in with a smaller piece.

I would put the top together, then drill out the knots with a hole saw and glue in a corresponding sized dowel in a contrasting color. I think something like that would look really good. Also a round dowel on the joints going all the way through would add strength to the joint.

In mesquite we find large holes, knots, worm holes, etc… I use fiberglass resin that is sold at Lowes or home depot. I follow the directions on the label except I go ahead and add saw dust in the resin to add substance and to thicken the product to my desired thickness. Dries fairly fast and dries very hard. Can be used to fill large areas. I try to be neat when working with it so I can avoid any excessive sanding when it is completely dried. Sanding the resin is not easy. Otherwise it works very well for us.

Fill them with Bondo automotive body fill. Sounds crazy but works great its weather proof won’t crack won’t fall out and it dries fast and sands easy. I use it all the time and have never had a problem with it.

I agree with Lee Barker and CharlieM1958. I used to work at a building site in South Lyon, Michigan, and we used it all the time to fill dents in steel entry doors. Just overfill it a bit, sand it, paint it, done. The only problem with using it on your workbench is that the color is pink when dry, but you could put those filled in boards on the bottom side. I just looked at prices for bondo: 6$ for a guart versus $26 for 12 oz for the products mentioned here.